Oh absolutely, that's a given.
Though I'm comparing to other factions in TOW rather than our 8th book. If anything, this is closer to our 6th book.
Let's take Blood Knights (BK) for example:
Compared to their closest counterparts in other armies, the chosen chaos knights (CCK) and the grail knights (GK) (same unit type, very similar points cost, similar equipment and profile):
- M8 for GK, M7 for BK and CCK
- WS6 for GK, WS5 for BK and CCK
- S4, T4, W1 for all
- I5 for GK, I4 for BK and CCK
- 2A for all
- Ld9 for GK and CCK, Ld7 for BK
- Same command options for all
- All can have hand weapons and lances
- All have barding, shields and heavy armour but GK cannot take plate armour which CCK and BK can
- BK take up to 50pts banner, GK and CCK take up to 100pts
- All can take a 25pt magic weapon on champion, GK can also give him a knightly virtue, BK can give him a vampiric power
- Close order, countercharge, swiftstride, first charge for all
- 6+ Ward for CCK and GK (sometimes 5+), 6+ regen for BK (and flammable)
- All have ways of mitigating or rerolling fear, terror, panic
- GK can reroll 1s when charging
- Costs (with lances): GK - 38pts, BK - 39pts, CCK - 38pts
So all in all they look very similar, with the Grail Knights (in my opinion) edging it out due to their higher WS, Initiative and more movement (both greater M and bonuses when charging). However, Grail Knights are not all that much better due to the quite significant lack of full plate. Taking mark of Khorne on CCK does make them much more deadly, though it comes at the cost of Frenzy.
I think ultimately it comes down to how well these units can be supported by the rest of the army, which is an area where Blood Knights uncharacteristically shine now. Van Hel's, Hellish Vigour, Mortis Engines and Invocation of Nehek all seem to work on Blood Knights (as far as I can tell). We have ways of easily improving their movement, weapon skill and initiative and most importantly we can resurrect fallen Blood Knights. I don't know how much synergy their counterparts can benefit from but for Blood Knights it seems like a lot. Maybe a touch too much.
Of course, playing games likely will change my perception of this, perhaps it's too difficult to stack buffs on Blood Knights, maybe it will never happen in a real game. Currently all I can say is that the potential is there and I'm not sure how to feel about it. On the one hand Blood Knights should feel strong, they are some of the most fearsome cavalry in the game. On the other hand, classically their strength has always come from strong profiles and rules but with little synergy with the rest of the army, given that they are not summoned cadavers but vampire knights.
Anyway, those are just my thoughts on the design of Blood Knights on paper. I think they've changed a lot in a very interesting way and are probably going to be used very differently now.